Samsung SyncMaster 226BW

[retiredcaps]

Re: Samsung SyncMaster 226BW

My cheap(works nicely though) capacitance meter from ebay arrived today.

Some multimeters have capacitance check built in.

It seems the small 47uF 50V cap was actually fine

uF may be fine, but what about ESR?

So its probably a safe bet to replace all caps on the board except the 450V one and the 47uF one.

A high quality low ESR Panasonic FC 47uF 50V costs 34 cents at digikey.com. At that price, why not replace it given that you don't know if the existing 47uF cap is within ESR specs or not?

I'll take a Panasonic FC over "CHNG" anyday.

[EGuevarae]

Re: Samsung SyncMaster 226BW

680uF New (Nichicon HD): ~730uF (can caps arrive overrated?)
mastertheknife.

Up to 20%.This is normal.

Wish i also had an ESR meter, but those seem too expensive for now.
mastertheknife.

Would be more useful than a capacitance meter in some cases, but yes, more expensive.It is safer to change the whole set of caps to avoid doing rework in the future .

[mastertheknife]

Re: Samsung SyncMaster 226BW

A high quality low ESR Panasonic FC 47uF 50V costs 34 cents at digikey.com. At that price, why not replace it given that you don't know if the existing 47uF cap is within ESR specs or not?

I'll take a Panasonic FC over "CHNG" anyday.

Hi retiredcaps,
I would have prefered replacing all caps, it sure would save re-opening the unit. Regarding the 47uF cap, i couldn't order from digikey so i had to order from ebay and what was i found was caps kit for the 226BW. In the pictures they are Nichicon PW (which they actually are, except the 47uF one and 330uF sadly and i did not know this until arrival).
I would order 47uF if i could, I have more than two 226BWs in my house and would love replacing the caps for all of them, but so far im unable to find low ESR 47uF 50V on ebay.
Digikey is great and i wish they would add an option to ship using First Class mail because right now $35+ just for shipping is just not worth it for me. Same goes for Mouser. I've tried checking RS components, but all prices on their website are on arrival and i can't confirm an order before knowing how much i will have to pay.

mastertheknife

[GR3Y5H3ART]

Re: Samsung SyncMaster 226BW

if anyone can help me with possibly having to replace the CCFL Bulbs after replacing all Caps on Two of Three boards:
https://www.badcaps.net/forum/showthread.php?t=13086

[jetadm123]

Re: Samsung SyncMaster 226BW

Hi retiredcaps,
I would have prefered replacing all caps, it sure would save re-opening the unit. Regarding the 47uF cap, i couldn't order from digikey so i had to order from ebay and what was i found was caps kit for the 226BW. In the pictures they are Nichicon PW (which they actually are, except the 47uF one and 330uF sadly and i did not know this until arrival).
I would order 47uF if i could, I have more than two 226BWs in my house and would love replacing the caps for all of them, but so far im unable to find low ESR 47uF 50V on ebay.
Digikey is great and i wish they would add an option to ship using First Class mail because right now $35+ just for shipping is just not worth it for me. Same goes for Mouser. I've tried checking RS components, but all prices on their website are on arrival and i can't confirm an order before knowing how much i will have to pay.

mastertheknife

Ouch! $35 to ship to Israel?!! One thing you could do is try measuring the voltage across the 47uf cap. If it's a startup cap, then it's probably under 20V. The 50V cap used seems to be the standard because it's cheap and readily available. I've heard of other members using lower voltage caps like 25-35V. Measure the voltage first before making any decision.

[PlainBill]

Re: Samsung SyncMaster 226BW

if anyone can help me with possibly having to replace the CCFL Bulbs after replacing all Caps on Two of Three boards:
https://www.badcaps.net/forum/showthread.php?t=13086

A word to the wise - triple posting is a good way to get ignored.

PlainBill

[retiredcaps]

Re: Samsung SyncMaster 226BW

A word to the wise - triple posting is a good way to get ignored.

Not only does it confuse people, but it wastes time because people duplicate efforts to help.

Posting inline and offsite are also discouraged.

[GR3Y5H3ART]

Re: Samsung SyncMaster 226BW

Not only does it confuse people, but it wastes time because people duplicate efforts to help.

Posting inline and offsite are also discouraged.

ok...sry i am still a

[mconine]

Re: Samsung SyncMaster 226BW

Hi. I just registered to let you know that I'm sitting here looking at my new SyncMaster 226BW monitor. I rescued it from the dumpster and it would do nothing except blink at a very rapid rate. I did a Google search to try to determine what might be wrong. This site popped up first.

After reading this thread all the way through I opened the monitor up and sure enough 5 of the caps were bulging and 2 of those showed signs of leaking. I ordered 6 new caps (I also replaced the only one that didn't show damage) from Mouser Electronics (also because of comments on this forum).

Tonight I replaced the caps, turned it on and it works great!

By the way, I'm a total novice at electronics and had never attempted anything like this before.

Thanks for all the great info. And thanks for the 'new' monitor!

Mike

[mastertheknife]

Re: Samsung SyncMaster 226BW

I messed up again, not sure even how.

When fixing the "bad" 226BW i opened up my own 226BW (good) to compare readings on both boards.
After fixing the bad board, i closed the monitor and the monitor works like new, and still works.

But i noticed the good board had a plagued 330uF capacitor, so i figured i will order caps from ebay to replace all caps while the monitor is still open.
Unable to order from digikey or mouser due to expensive shipping ($30+ because first class is not available for international orders) so i had to order from eBay.
I replaced the 330uF cap with Rubycon ZL 330uF 25V, the 820uF caps with Nichicon HD(M) 820uF 25V and the 680uF caps with Nichicon HD(M) 680uF 25V.
Made sure to clean the soldering joints with q-tips and alcohol to remove any dirt or flux, left the board to dry overnight and powered up the monitor today.

The monitor powered up, but after using the computer for some time, i noticed that the backlight dims for a 1/4 of a second often. After few more minutes, the backlight turned off and ever since, its off and won't turn back on.
I took apart the monitor again, took out the power supply. To my suprise, all of the caps are ok, however fuse F301 is blown (open circuit).

Could the new 680uF caps (the caps in the inverter section) be possibly bad?
I noticed they look a little different from the 820uF caps, and according to nichicon's datasheet, their height should be 20mm, but they are actually 16mm height. The seller told me not to worry and that casing for capacitors changes all the time (USA seller). Before soldering the capacitors to the board, i measured their capacitance with a capacitance meter: almost all 680uF capacitors measured ~450uF except two which measured ~730uF, which are the two that i chose to solder to the board. The date (H0912) from what i understand is december 2009.

EDIT: Added a picture of the fuse and the back of the board. Ignore the solder on the long lines, i did that after the fuse blew.

Confused again what went wrong,
mastertheknife.

[mastertheknife]

Re: Samsung SyncMaster 226BW

I took out the blown fuse. On the fuse there is only "3A E" on both sides.
From another thread, this seems to be a 3A 125V fast-acting(5s at 200%) fuse.
i will order some and hopefully it won't blow again. And if it does, i will try putting back the original capXcon 680uF caps to see if the problem comes from the new 680uF capacitors and i will report back.
Ideas, thoughts, theories, suggestions and anything else is welcome.

Seems like i have bad luck with those monitors or with electronics in general,
I am the electronics destroyer.
mastertheknife

[alexanna]

Re: Samsung SyncMaster 226BW

Make sure that the capacitors you replaced have good solder joints, gently rock the top or the capacitor and look for movement on the solder pads.

[mastertheknife]

Re: Samsung SyncMaster 226BW

Make sure that the capacitors you replaced have good solder joints, gently rock the top or the capacitor and look for movement on the solder pads.

Good suggestion.
They don't seem to move, so i suspect the joints are okay. Also, none of the capacitors are shorted and resistance between F301 and ground is very high, so i'm not sure where things went wrong.
I will only be able to power up this board again in 2 weeks when the fuses arrive.

Thank you,
mastertheknife

[retiredcaps]

Re: Samsung SyncMaster 226BW

almost all 680uF capacitors measured ~450uF except two which measured ~730uF,

The caps that measure 450uF are out of spec. (M) indicates +/- 20%.

680 x 0.8 = 544uF.

[mastertheknife]

Re: Samsung SyncMaster 226BW

The caps that measure 450uF are out of spec. (M) indicates +/- 20%.

680 x 0.8 = 544uF.

Also, these Nichicon HD(M) 680uF 25V caps are all 10x16mm height, while the nichicon HD datasheet states 10x20mm for the 680uF 25V.
Is it likely that they are fakes, and perhaps they are the cause to the blown fuse? (They sit between positive from F301 and ground)

Also, this is what i received from the seller when i asked him about why these caps are 10x16mm instead of 10x20mm, this was his response:
"Yes these are HD(M) series.... Some case sizes are different but same Capacitance value. They change case very often depending on the manufacture."

Thank you,
mastertheknife.

[pebe292]

Re: Samsung SyncMaster 226BW

Hi Mastertheknife!
I can't find any fuse, can you help me to find it?
Thank you

[retiredcaps]

Re: Samsung SyncMaster 226BW

I took a random sample of my Rubycon 1000uF, 470uF, 2200UF caps (MCZ and ZL) and tested them for capacitance. All measured higher than the stated values.

If these are new 680uF caps measuring 450uF, I would say you got fakes or bad caps.

[mastertheknife]

Re: Samsung SyncMaster 226BW

Hi Mastertheknife!
I can't find any fuse, can you help me to find it?
Thank you

Hi, i circled the fuses in the attached picture.

mastertheknife

[mastertheknife]

Re: Samsung SyncMaster 226BW

I took a random sample of my Rubycon 1000uF, 470uF, 2200UF caps (MCZ and ZL) and tested them for capacitance. All measured higher than the stated values.

If these are new 680uF caps measuring 450uF, I would say you got fakes or bad caps.

Thank you for the test. And yes, although i put ones that measured ~730uF. 6 out of the 8 measured ~450uF and the other two measured ~730uF, which are the ones i put in.
I will put new\old ones back when i receive the new fuses.

Thank you,
mastertheknife.

[retiredcaps]

Re: Samsung SyncMaster 226BW

Out of curiousity, I even tested my "bad" Capxon caps. These are caps that didn't bulge, but I removed anyways due to "guilt by association".

The 3 or 4 "bad" non bloated Capxons all tested above their stated uF.